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Enter a 5-character code such as P0420, P0301, or P0457.

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Codes starting with P are engine and transmission, B are body, C are chassis, and U are network communication. A 0 as the second character means a generic code shared by all makes; a 1 means a manufacturer-specific code, so its meaning depends on your brand.

A steady check engine light usually means get it checked soon. A flashing check engine light means an active misfire: reduce speed and stop driving as soon as it is safe.

That doesn't look like an OBD-II code

A valid code is one letter (P, B, C, or U) followed by four characters, for example P0420.

P0430 Catalytic converter efficiency below threshold (Bank 2)

Can I drive with P0430?

Drive soon

OK to drive for now, but get it fixed within days to a couple of weeks, or the damage and the bill can grow.

Not dangerous right now, but a failing converter can clog and cost power, and the car will fail an emissions test.

What does P0430 mean?

The oxygen sensor after the catalytic converter shows the converter on bank 2 is no longer cleaning the exhaust as well as it should. Bank 2 is the side of a V6 or V8 engine that does not have cylinder 1. P0420 is the same fault on bank 1.

What causes P0430?

A worn converter is most common, but a bank 2 rear oxygen sensor or exhaust leak can set the same code. Fix any misfire or fuel codes first.

  1. Worn-out catalytic converter
  2. Faulty downstream (rear) oxygen sensor
  3. Exhaust leak near the oxygen sensors
  4. Misfires or a rich mixture that damaged the converter
  5. Outdated engine computer software

How much does it cost to fix P0430?

$150 – $2,500

Oxygen sensor or exhaust leak repair: $150–$500. New catalytic converter: $1,000–$2,500 or more, depending on the vehicle. Rule out the cheaper causes first. If P0420 is also set, both converters may be worn, so get one quote covering both.

What are the symptoms of P0430, and how can I confirm it?

Usually just the light. A clogged converter can cause a rotten-egg smell, weak acceleration, or a rattle under the car. To confirm, scan for other codes, listen for exhaust leaks on the bank 2 side, and on live data check that the bank 2 rear oxygen sensor stays steadier than the front one.

Will P0430 fail an emissions test, and should I clear it?

It fails any inspection that reads the OBD-II computer, and clearing it right before the test does not help because the readiness monitors reset. After a repair, clear it and drive normally for several days, including some steady highway driving. If P0430 returns, the converter or sensor still needs work.

Confirm the code yourself

A low-cost scanner lets you read the code, clear it, and see if it comes back before paying for a diagnosis.

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